Lithographic Apparatus and Device Manufacturing Method

Abstract

A clamping device can be configured to clamp an object on a support. The clamping device can include a first device configured to exert an attracting force on the object, and a second device configured to exert a rejecting force on the object. The first device and second device can be configured to simultaneously exert an attracting and a rejecting force on the object to shape the object to a desired shape before clamping of the object on the support. A method is provided for loading an object on a support, comprising the steps of shaping the object in a desired shape spaced from the support. The shaping can include subjecting the object simultaneously to an attracting force pulling the object toward the support and a rejecting force pushing the object away from the support, and clamping the object on the support.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]This application claims priority to U.S. Application 60 / 935,381 filed Aug. 9, 2007. The subject matter of that application is incorporated herein as if fully set forth.BACKGROUND[0002]1. Field of the Invention[0003]The present invention relates to a clamping device and a method for clamping an object on a support. The present invention further relates to a lithographic apparatus and a method for clamping a substrate on a substrate support of a lithographic apparatus.[0004]2. Description of the Related Art[0005]A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In such a case, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can...

AI Technical Summary

Benefits of technology

[0010]Applicants have determined that it is desirable to provide a substrate support having a holding arrangement for substrates, wherein internal stresses in a substrate due to clamping forces are substantially decreased. Furthermore, it is desirable to provide a clamping method with which a warped substrate may be clamped on a substrate support in a manner that does not introduce stresses in the substrate and / or the potential for overlay errors.

Problems solved by technology

However, substrates may not be straight.

However, as a result, stresses may be induced in the substrate when it is clamped on the supporting surface.

These stresses may adversely affect the final product quality.

The clamped forced re-shaping of the substrate may also adversely affect overlay performance of the projections of the lithographic apparatus in that they may not properly align thereby reducing product quality.

Images